WASHINGTON — Republicans from the Deep South could control the gavel on eight Senate committees come January, a sizable concentration of power for a region once dominated by Democrats.

Seniority is the main ingredient for awarding committee chairmanships. When Republicans won the Senate majority on Tuesday, it elevated a sizable number of longtime Southern senators who have been biding their time in the minority.

"I think it means our state and our region will have more effective representation in the United States Senate," Sen. Lamar Alexander, R-Tenn., said Wednesday. "The national Democratic party has left the South, and many of the former Democrats and independents are voting in the Republican primary."

Republican senators will decide on their committee chairmen in the coming weeks. While there could be surprise trades or challenges, here are the likely Southern gavel holders:

"There is a major surge of Southern strength in the Senate, and it's reminiscent of the Southern strength during the old solid South days of Democratic dominance," said Ferrel Guillory, director of the Program on Public Life at the University of North Carolina and Southern political analyst.

The region was controlled by conservative Democrats for most of the 20th century, accumulating enough seniority to wield important committee gavels for decades. As a bloc, they advocated for farm subsidies and jobs programs for their struggling rural economies.

They also opposed the civil rights agenda of President Lyndon Johnson in the mid-1960s.

Eventually, the GOP's "Southern strategy" took hold in the 1980s, and the region transitioned to two-party representation for a few years before flipping almost completely to GOP control.

Many of those Southern Republican senators now possess the necessary seniority to retake the reins of the Senate and reassert the South as a regional power.

"Now this is the Republican base, the dominant base, and it is becoming the dominant power center," said Norman Ornstein, a political scholar at the American Enterprise Institute.

Led by Mitch McConnell of Kentucky, a fellow southerner and the presumed Senate majority leader next year, the future committee chairmen will choose which issues to showcase, which administration officials to interrogate, and which bills to pass or kill.

Whether their shared geography translates into a shared legislative agenda is an open question. The group includes different types of Republicans. Alexander has built a career on bipartisan negotiations and voted for the Senate deal on immigration reform, but Sessions generally avoids compromising with Democrats and was a leading opponent of the Senate immigration bill.

"You have some who are right over on the right end of the spectrum, and others who are really sort of in the center of the Republican Party, although the center has moved sharply right," Ornstein said.

Sen. Thad Cochran, R-Miss. pictured here on election night, is poised to take the gavel of the Appropriations panel next year. Cochran survived a tough primary and then sailed through the general election as the GOP took the majority.(Photo: Rogelio V. Solis, AP)

Chairmanships no longer allow senators to shower their home states with federal dollars, as when the Appalachian Regional Commission was created in 1965 and funneled billions to the South to fight poverty, build roads and create jobs.

Republicans have imposed a six-year limit on chairmanships and have banned the practice of inserting money for home-state projects, or earmarks, into spending bills. The GOP's priorities are to cut spending, shrink government and reduce the federal deficit.

Many Southern Republicans also campaigned on a platform of rolling back President Obama's agenda on issues such as environmental regulation, health care and immigration.

"That's their dilemma now," Guillory said. "What do they do for the region within the boundaries of the opposition philosophy they've propounded?"

The only two Southeastern Democratic senators left after Tuesday's GOP rout are Sen. Mary Landrieu of Louisiana, who is considered vulnerable in a Dec. 6 runoff election against Republican Bill Cassidy, and Sen. Bill Nelson of Florida.

"What's also true is that with all that clout and power, Republicans in the South continue to grow as a proportion of the party," Ornstein said. "And with the presidential nominating process, you really can't get there without going through the South."